Two investigational mRNA vaccines have demonstrated complete protection against the lethal Andes hantavirus in a pivotal animal study, requiring only a single intramuscular dose.
Researchers tested both modified and non-modified mRNA formulations in female golden Syrian hamsters, the only model that accurately mirrors fatal hantavirus pulmonary syndrome in humans. All vaccinated animals, even those receiving the lowest 1 μg dose, survived a lethal viral challenge without developing disease. In stark contrast, four of five unvaccinated control hamsters succumbed to the infection within 10 days.
The vaccines generated early, dose-dependent IgG antibody responses by day 14 post-vaccination. Both platforms proved equally immunogenic at each dose level.
These results carry heightened urgency as Andes virus remains unique among hantaviruses for its capacity to transmit between humans via respiratory secretions. A May 2026 outbreak aboard the MV Hondius cruise ship originating in Argentina caused 13 cases and three deaths, scattering nearly 150 high-risk contacts across 23 countries.
No vaccines or preventive treatments for Andes hantavirus currently hold approval from the U.S. Food and Drug Administration or the European Medicines Agency. Researchers indicate the rapid protection and dose-sparing efficacy support an accelerated path toward human clinical trials.